Answer:

Step-by-step explanation:
we know that
<u><em>Combinations</em></u> are a way to calculate the total outcomes of an event where order of the outcomes does not matter.
To calculate combinations, we will use the formula

where
n represents the total number of items
r represents the number of items being chosen at a time.
In this problem

substitute

simplify



is proved
<h3><u>
Solution:</u></h3>
Given that,
------- (1)
First we will simplify the LHS and then compare it with RHS
------ (2)

Substitute this in eqn (2)

On simplification we get,


Cancelling the common terms (sinx + cosx)

We know secant is inverse of cosine

Thus L.H.S = R.H.S
Hence proved
Step-by-step explanation:
By Law of Indices, a^m * a^n = a^(m+n).
Therefore 8³ * 8⁵ = 8^(3+5) = 8⁸.
this is a binomial problem: p = 0.7 and q = 0.3
a) (0.7)^6
b) (6C4)(0.7)^4(0.3)^2
c) Pr ( at least 4) = Pr(4) + Pr(5) + Pr(6) = (6C5)(0.7)^5(0.3) + (0.7)^6
d) Pr (no more than 4) = 1 - Pr(at least 4) = 1 - (answer from c)